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CVE-2021-47217

x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails Check for a valid hv_vp_index array prior to derefencing hv_vp_index when setting Hyper-V's TSC change callback. If Hyper-V setup failed in hyperv_init(), the kernel will still report that it's running under Hyper-V, but will have silently disabled nearly all functionality. BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:set_hv_tscchange_cb+0x15/0xa0 Code: <8b> 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08 ... Call Trace: kvm_arch_init+0x17c/0x280 kvm_init+0x31/0x330 vmx_init+0xba/0x13a do_one_initcall+0x41/0x1c0 kernel_init_freeable+0x1f2/0x23b kernel_init+0x16/0x120 ret_from_fork+0x22/0x30

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 93286261de1b46339aa27cd4c639b21778f6cade before b20ec58f8a6f4fef32cc71480ddf824584e24743; affected 93286261de1b46339aa27cd4c639b21778f6cade before b0e44dfb4e4c699cca33ede431b8d127e6e8d661; affected 93286261de1b46339aa27cd4c639b21778f6cade before 9c177eee116cf888276d3748cb176e72562cfd5c; affected 93286261de1b46339aa27cd4c639b21778f6cade before 8823ea27fff6084bbb4bc71d15378fae0220b1d8; affected 93286261de1b46339aa27cd4c639b21778f6cade before daf972118c517b91f74ff1731417feb4270625a4
Linux / Linuxaffected 4.16; unaffected 0 before 4.16; unaffected 4.19.218 through 4.19.*; unaffected 5.4.162 through 5.4.*; unaffected 5.10.82 through 5.10.*; unaffected 5.15.5 through 5.15.*; unaffected 5.16 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.